Field of the Invention
The present invention relates to an image sensor and a method of manufacturing the same.
Description of the Related Art
A white spot is given as a drawback unique to an image sensor. The white spot is noise generated when an impurity such as a heavy metal or a crystal defect exists in a photoelectric conversion element. A defective layer is formed in a semiconductor substrate with respect to this noise and the impurity is gettered in the defective layer by annealing during a manufacturing process, reducing noise. In recent years, a technique of forming a defective layer in an element isolation region in the vicinity of a photoelectric conversion element has been proposed. Japanese Patent Laid-Open No. 2009-194269 has disclosed a structure which includes a defective layer in a position deeper than the bottom of a trench element isolation (STI) arranged above an element isolation region out of element isolation regions between photoelectric conversion elements.